Biochemical and Biomolecular Engineering Commons^™

Life-Cycle Energy And Ghg Emissions Of Forest Biomass Harvest And Transport For Biofuel Production In Michigan, Fengli Zhang, Dana M. Johnson, Jinjiang Wang

College of Business Publications

High dependence on imported oil has increased U.S. strategic vulnerability and prompted more research in the area of renewable energy production. Ethanol production from renewable woody biomass, which could be a substitute for gasoline, has seen increased interest. This study analysed energy use and greenhouse gas emission impacts on the forest biomass supply chain activities within the State of Michigan. A life-cycle assessment of harvesting and transportation stages was completed utilizing peer-reviewed literature. Results for forest-delivered ethanol were compared with those for petroleum gasoline using data specific to the U.S. The analysis from a woody biomass feedstock supply perspective uncovered …

Towards Intensified Protein Refolding And Purification On Size Exlusion Chromatography: Fundamental Studies And Mathematical Modelling, Pegah Saremirad

Electronic Thesis and Dissertation Repository

For industrial recombinant-protein processes, protein refolding and purification are crucial steps towards the recovery of considerable numbers of active and safe therapeutic products. In this thesis, intensification strategies for protein refolding and purification processes are explored. Development of an intensified process aims at simultaneous optimization of process performance indicators, namely: refolding yield, product purity, volumetric productivity and solvent consumption which in turn decrease the cost and time constraints to market.

The first strategy investigated related to multivariable experimental work using size exclusion chromatography (SEC) as a refolding method and a denatured/reduced model protein (lysozyme). SEC was selected due to its …

A Versatile Microparticle-Based Immunoaggregation Assay For Macromolecular Biomarker Detection And Quantification, Haiyan Wu, Yu Han, George G. Chase, Qiong Tang, Chen-Jung Lee, Bin Cao, Jiang Zhe, Gang Cheng

Dr. Jiang Zhe

The rapid, sensitive and low-cost detection of macromolecular biomarkers is critical in clinical diagnostics, environmental monitoring, research, etc. Conventional assay methods usually require bulky, expensive and designated instruments and relative long assay time. For hospitals and laboratories that lack immediate access to analytical instruments, fast and low-cost assay methods for the detection of macromolecular biomarkers are urgently needed. In this work, we developed a versatile microparticle (MP)-based immunoaggregation method for the detection and quantification of macromolecular biomarkers. Antibodies (Abs) were firstly conjugated to MP through streptavidin-biotin interaction; the addition of macromolecular biomarkers caused the aggregation of Ab-MPs, which were subsequently …

Zwitteration Of Dextran: A Facile Route To Integrate Antifouling, Switchability And Optical Transparency Into Natural Polymers, Bin Cao, Linlin Li, Haiyan Wu, Qiong Tang, Bingbing Sun, He Dong, Jiang Zhe, Gang Cheng

Dr. Jiang Zhe

This communication reports a facile method for zwitteration of dextran with carboxybetaine (CB), which integrates superior antifouling properties, switchability between zwitterionic and cationic forms, as well as enhanced optical transparency into one polysaccharide material. This study provides a new avenue for generating multifunctional zwitterionic CB materials in situ.

Single-And Multi-Hole Baffles-A Heat Transfer And Fluid Flow Control For Hydrothermal Growth, Edward Evans, Hongmin Li, Guo-Xiang Wang

Dr. Guo-Xiang Wang

Hydrothermal solution growth is an important technique to grow high-quality single crystals. An autoclave, a closed cylindrical low-carbon steel vessel, is used to grow the large size crystals. A baffle located at the median height divides an autoclave into two chambers. Previous numerical studies indicate that the buoyancy-driven flow within an autoclave is very sensitive to the temperatures on the wall established by the heating. Baffles are required to establish the conditions for growth of high quality single crystals. This paper presents a numerical study of the effects of various baffles on the fluid flow and temperature fields in an …

Natural Convection Flow Structures And Heat Transfer In A Model Hydrothermal Growth Reactor, Hongmin Li, Minel Braun, Edward Evans, Guo-Xiang Wang, Govind Paudel, Jason Miller

Dr. Guo-Xiang Wang

Due to the experimental difficulties brought about by high pressure and temperature growth conditions, flow and heat transfer in industrial hydrothermal autoclaves for the growth of single quartz crystals have been studied mostly numerically. To date, most of the numerical models and associated results are not experimentally validated; only qualitative validation data from experiments done during actual crystal growth production is partly available. In this study, the authors used a model simulated reactor represented by an enclosure with two lower half sidewalls uniformly heated while the upper half sidewalls are uniformly cooled. Flow structures in the reactor are qualitatively visualized …

A Three-Dimensional Conjugate Model With Realistic Boundary Conditions For Flow And Heat Transfer In An Industry Scale Hydrothermal Autoclave, Hongmin Li, Edward Evans, Guo-Xiang Wang

Dr. Guo-Xiang Wang

This paper presents a conjugate heat transfer model for industry size hydrothermal autoclaves. The electric heating on the wall outside surfaces is represented by constant heat fluxes. The circumferential heat flux deviation is introduced for the asymmetric factors from the surroundings. The results indicate that the temperature at the solution/wall interface is far from uniform. Circumferential temperature deviation is large enough to establish an asymmetric flow. To accurately simulate flows in industry autoclaves, one needs to use the conjugate model. The growth environment in current industry autoclaves, however, can be improved by establishing a uniform temperature on the wall/solution interface.

Three-Dimensional Flow Of Solution In An Industry-Size Hydrothermal Autoclave Subjected To Non-Uniform Heating Effects Of A Baffle On Flow And Temperature Separation, Hongmin Li, Guo-Xiang Wang, Edward Evans

Dr. Guo-Xiang Wang

Hydrothermal growth takes place in a closed cylindrical container called an autoclave. Natural convection flow of an aqueous solution at a high temperature and a high pressure carries the nutrient. The high temperature growth condition and the natural convection flow are maintained by two independently controlled electrical heaters on the outside of the autoclave. In practice, the heating is circumferentially non-uniform. Many theoretical and numerical studies, however, assume axially symmetric heating conditions. This paper presents a numerical analysis of the three-dimensional heat transfer and fluid flow with a non-uniform heating condition. The analysis is based on an industry-size autoclave with …

Adaptation And Robustness In A Chemotaxis Network, Beini Chen, Steve Abel

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Adaptation is a behavior of biological systems in which a sustained change in input signal leads to a transient output response that returns to the pre--‐stimulated output level. Cells use adaptation to maintain sensitivity to the changes in their environment and to remain in homeostasis while the input signal is perturbed. Signaling networks in both prokaryotic and eukaryotic cells demonstrate adaptation, which is a common feature of chemotaxis, a signal transduction process that enables cells to sense chemical gradients in their extracellular environment and to adjust their movement in response. In the case of Escherichia coli, the bacteria swim in …

One-Step Production Of Long-Chain Hydrocarbons From Waste-Biomass-Derived Chemicals Using Bi-Functional Heterogeneous Catalysts, Cun Wen, Elizabeth Barrow, Jason Hattrick-Simpers, Jochen Lauterbach

Jason R. Hattrick-Simpers

n this study, we demonstrate the production of long-chain hydrocarbons (C8+) from 2-methylfuran (2MF) and butanal in a single step reactive process by utilizing a bi-functional catalyst with both acid and metallic sites. Our approach utilizes a solid acid for the hydroalkylation function and as a support as well as a transition metal as hydrodeoxygenation catalyst. A series of solid acids was screened, among which MCM-41 demonstrated the best combination of activity and stability. Platinum nanoparticles were then incorporated into the MCM-41. The Pt/MCM-41 catalyst showed 96% yield for C8+ hydrocarbons and the catalytic performance was stable over four reaction …

Integrating Top-Down And Bottom-Up Scaffolding Tissue Engineering Approach For Bone Regeneration, M. Ramalingam, Esmaiel Jabbari, S. Ramakrishna, A. Khademhosseini

Esmaiel Jabbari

No abstract provided.

Effect Of Surfactants And Cosurfactants On The Phase Separation Temperature And Volatility Of Methanol/Hydrocarbon/Water Blends, Michael Cheung

Dr. Michael Cheung

The effects of several surfactants and cosurfactants on the phase separation temperature and Reid vapor pressure of methanol/hydrocarbon/water blends were investigated.

Polymerization Of Microstructured Aqueous Systems Formed Using Methyl Methacrylate And Potassium Undecenoate, Michael Cheung

Dr. Michael Cheung

No abstract provided.

Formation Of Polymeric Foams From Aqueous Foams Stabilized Using A Polymerizable Surfactant, Michael Cheung

Dr. Michael Cheung

Polymerization of foams formed by purging with nitrogen an aqueous precursor system made up of a polymerizable surfactant, a monomer, and a cross-linking agent yielded stable polymeric foams. The precursor system for foaming contained hydrophobic components (methyl methacrylate as monomer and ethylene glycol dimethacrylate as cross-linking agent) in water and was stabilized using the polymerizable surfactant potassium acrylamidostearate. The phase-behavior study for the precursor system was conducted followed by an investigation of the stability of the foams obtained on purging with nitrogen. Sonicating the precursor systems during the process of purging with nitrogen gas followed by polymerization resulted in aqueous …

Effects Of Heptanoic And Oleic Acid On The Phase Separation Temperatures Of Methanol/Hydrocarbon/Water Mixtures, Michael Cheung

Dr. Michael Cheung

The efficacy of heptanoic and oleic acids as phase separation temperature depressants for methanol/hydrocarbon/water blends was examined.

Characterization And Polymerization Of Middle-Phase Microemulsions In Styrene/Water Systems, Michael Cheung

Dr. Michael Cheung

The products of photopolymerizing middle-phase microemulsions containing sodium dodecyl sulfate as a surfacant, styrene as a monomer, NaCL or NaSCN as electrolyte, and either 2-pentatol or a combination of 5-hexene-1, 2-diol and sodium styrenesulfonate as a cosurfacant were characterized by using differential scanning calorimetry, gel permeation chromatography, and scanning electron microscopy (SEM).

Microstructured Polymers Via Photopolymerization Of Non-Aqueous Organized Solutions, Michael Cheung

Dr. Michael Cheung

Structurally organized solutions containing monomers in an ethylene glycol (EG) medium were formed and polymerized to produce polymeric solids with various morphologies, and also unique thermal and mechanical properties. Previous research had demonstrated the formation of microemulsions in an aqueous medium containing methyl methacrylate (MMA) and acrylic acid (AA). However, the non-aqueous mixtures of MMA and AA with EG did not yield conventional microemulsions. Molecularly dispersed solutions were formed in the bulk of the phase diagram, while compositions closer to the demixing line exhibited critical behaviour. This paper presents the first account of the use of mixtures exhibiting critical behaviour …

Formation Of Porous Polymeric Structures By The Polymerization Of Single-Phase Microemulsions Formulated With Methyl Methacrylate And Acrylic Acid, Michael Cheung

Dr. Michael Cheung

No abstract provided.

Acid And Base Effects On The Morphology Of Composites Formed From Microemulsion Polymerization And Sol--Gel Processing, Michael Cheung

Dr. Michael Cheung

Phase behaviour studies were performed for microemulsions, containing organic monomers (methyl methacrylate and acrylic acid), inorganic monomer (tetraethoxy silane (TEOS)), a cross linking agent (ethylene glycol dimethacrylate) and water, stabilized by a cationic surfactant, cetyltrimethylammonium bromide. Single phase transparent microemulsions were formed over a considerable portion of the composition domain. The effects of an acid, hydrochloric acid (HCl), and a base (NH4OH) on the gel times were studied and the catalytic action of acid and base on the overall sol–gel reaction was analysed. Organic/inorganic polymer composites were obtained from the hydrolysis and polycondensation reactions of TEOS (sol–gel process) and polymerization …

Light Scattering Study Of Polymer Network Formation In A Supercritical Diluent, Michael Cheung

Dr. Michael Cheung

We have undertaken a study of the benefits of using near-critical and supercritical fluids in synthesizing microcellular foams. In this study, we use dynamic light scattering to study the formation of the polymer network directly in near-critical and supercritical freon-22. The polymer system studied is ethylene-glycoldimethacrylate+methylmethacrylate. We have previously obtained microcellular foams by direct polymerization in this system and this study elucidates the gelation process by tracking the correlation length of the inhomogeneities as a function of reaction time from the monomeric state to the gel transition.